The source--a page on MSN--says that it is not photoshopped nor manually created by paints. The glow-in-the-dark effect in some of Maldives beaches is thanks to ostracod crustaceans aka seed shrimps, who can emit blue light for several seconds. To make something as spectacular as the photo, though, a researcher said that there might be a mass mortality of ostracods. Reports of similar finding also come from Jamaica, Puerto Rico, and Belgium.
I'd love to see one before I die, but the sad story behind makes me feel so bad inside.